Most of the wireless communication devices are equipped with antennae, so as to transmit or receive an electromagnetic signal. In order to enhance a capability of transmitting or receiving the electromagnetic signal, usually a plurality of antennae is arranged to form an array antenna.
Along with the development of the array antenna, a phased-array antenna has emerged. The phased-array antenna mainly includes a phase shifter and a plurality of radiating elements arranged in an array form. The phase shifter is configured to shift a phase of the received electromagnetic signal, and each radiating element is configured to radiate outward the electromagnetic signal acquired after the phase-shifting. There is a certain phase difference between the signals radiated by the radiating elements. Through controlling a size of the phase difference between the signals radiated by the radiating elements, it is able to synthesize main beams in different orientations for scanning.
For a conventional phased-array antenna, its phase shifter includes a liquid crystal cell, which includes two planar substrates arranged opposite to each other form a cell. The plurality of radiating elements is arranged at an exterior wall of one of the planar substrates. The electromagnetic signal is introduced into the liquid crystal cell, and liquid crystals are deflected, so as to shift the phase of the electromagnetic signal. Then, the electromagnetic signal acquired after the phase-shifting is radiated outward by the plurality of radiating elements. During the operation of the antenna, in the case that a specific position is scanned by the main beam, its gain may be reduced dramatically. In order to prevent the reduction in the gain, a scanning range of the phased-array antenna is usually within −45° to +45° relative to an array plane normal. The application and development of the phased-array antenna are extremely limited by such a narrow scanning range.